Abstract
Purpose
Clavicular anatomy is variable and this has implications when osteosynthesis is undertaken especially while using the newer generation pre-contoured anatomical plates. This study aimed to examine the anatomy of the clavicle and its variations.
Methods
One hundred and forty three clavicles of unknown origin were analysed. Photographs were taken of each clavicle. A scale and electronic callipers were used to determine specific dimensions from six predefined areas of the bone. The length, diameters of the acromial and sternal heads, the diameter of the mid-clavicular segment and depths of both the medial and lateral curvatures were obtained.
Results
Clavicles studied ranged from 18.34 centimetres to 10.93 centimetres in length, with the mean length being 14.97 centimetres thus, demonstrating 7.41±1.38 centimetres variability in length between extremes of the clavicles measured. In general, left clavicles were found to be longer than right clavicles. Mid-clavicular segments showed a greater diameter on the left than right, with 1.07±0.17 centimetres difference between the extremes of diameters. The mean diameter of the sternal and acromial heads showed little variation at 2.36±0.38 centimetres and 2.54±0.47 centimetres respectively. Medial curvatures were found to be deeper than lateral curves (1.87±0.36 centimetres vs. 1.28±0.46 centimetres), although the lateral curves showed more bone to bone variation.
Conclusion
The results of this study define the dimensions of the clavicle and illustrate the wide variations in its anatomy. This variability shown in large group of cadaveric specimens would be immensely helpful to consider while designing the pre-contoured anatomical plates. In addition, surgeons should note these variations in the clavicular anatomy while undertaking osteosynthesis as these variations have the potential of causing a mismatch between the newer pre-contoured plates and the fractured clavicle fixation
